Geological Time: History of Ideas

Abstract

Early estimates of the Earth's age were restricted by literal interpretations of Genesis, but the geological time scale had
been greatly extended by the early nineteenth century. The development of stratigraphy encouraged the belief that the Earth's
history included a sequence of distinct periods stretching back to a period long before the appearance of humankind. Calculations
by nineteenth‐century physicists imposed a limit of at most 100 million years on estimates of the Earth's age, and most geologists
accepted this limit. It was only after the discovery of radioactivity that it became possible both to extend the scale of
geological time and to develop techniques for providing exact dates.